A counter-weight balanced X-ray frame structure of the aforedescribed kind is described in SE-C-7414800-8 and patent of addition SE-C-7605920-3 (both AO:s Metall & Mek. Verkstad). In this known kind of X-ray frame structure two longitudinally extending handles stretch along the major part of the length of the arm, of which handles one incorporates components for generating an operating field for releasing rotational movement of the arm, while the other handle incorporates components for generating a field for releasing the movement of the arm axially along the column.
Thus, when holding the one handle the arm can be moved vertically to a desired position, while when holding the other handle the arm can be swung to a desired rotational position. Naturally, both of these movements can be carried out simultaneously. As soon as one of the handles is released, the corresponding brake means is activated, so that the arm stops in the position occupied by the arm when the handle is released.
In other types of known X-ray frame structures, the release and application of corresponding brake means is effected by actuating switches provided on the arm and/or the frame structure.
When using an X-ray frame of the aforesaid kind in practice it is found that a number of arm setting positions occur relatively often. Consequently, there is a need for the possibility of setting one or more such positions in a more convenient manner, so that the operator can be relieved from a large part of the work associated with fine adjustment to the setting of the pendulum arm, and so that the operator can be made aware of whether or not the arm has actually reached the position desired, without having to make exhaustive checks in this respect.
This problem applies with all types of X-ray frames provided with pendulum arms, i.e. both when the arms are arrested at the moment when the operator releases a handle and when the operator is forced to manipulate one or more switches in order to activate or de-activate the braking function.